Lecture 3 BILD 3

What did Aristotle think about living things?

He believed living things never change and placed them on a ladder from lowest to highest (Scala Naturae).

What did Carolus Linnaeus do, and did he believe in evolution?

He gave living things two-part names (like Homo sapiens) and grouped similar things together. He did not believe in evolution; he thought God made each kind separately.

Who was Georges Cuvier, and what did he say about fossils?

He studied fossils and saw that old bones look different from animals today. But he didn't believe in evolution; he thought giant natural disasters wiped them out.

What is catastrophism?

Cuvier’s hypothesis that the belief that big, sudden disasters (like floods) destroyed old animals, and new ones just moved in from somewhere else.

What is stratigraphy / strata?

Layers of rock stacked on top of each other. Deeper layers are older, so older fossils are buried at the bottom.

What did James Hutton say about the Earth (gradualism)?

Huge things like canyons are carved slowly by everyday forces like rivers over a really long time.

What is Charles Lyell's principle of uniformitarianism?

The rules of nature work the same today as they did millions of years ago, changing the Earth very slowly.

Why were Hutton and Lyell important to Darwin?

They proved the Earth is super old. If the Earth wasn’t millions of years old, there wouldn’t have been enough time for living things to slowly evolve.

What did Jean-Baptiste de Lamarck get right?

He was the first to openly say that species change over time to fit where they live.

What is use and disuse?

Lamarck’s idea that body parts you use get bigger, and parts you don’t use shrink away (like a giraffe stretching its neck).

What is the inheritance of acquired characteristics?

Lamarck’s wrong idea that changes an animal gets during its own life are passed down to its babies (like a bodybuilder having a baby born with big muscles).

Why was Lamarck’s idea wrong?

Working out or stretching your body does not change your DNA, so your babies cannot inherit those changes.

What did Charles Darwin notice on his boat trip?

Animals on islands had special body shapes that matched the food they ate, like bird beaks shaped for cracking specific seeds.

What’s adaptation?

A helpful body part or behavior that an animal inherits which helps it survive and have babies.

How did Thomas Malthus inspire Darwin?

Malthus wrote that more babies are born than there is food to eat. Darwin realized this causes a fight to survive where only the best-suited make it.

Who was Alfred Russel Wallace?

A scientist who figured out the exact same idea of natural selection as Darwin around the same time.

Descent with modification

Over generations, kids look and act a little different from their parents, slowly changing the family tree over time.

Natural selection

When nature kills off individuals with bad traits, so individuals with helpful traits survive, have more babies, and become more common

What 3 things are needed for natural selection to happen?

Individuals can’t all look the same, some traits help you live or have more babies, and the trait must be passed down by genes.

Do individual animals evolve during their life?

No. You’re stuck with the genes you were born with. Only the whole group (population) changes over generations.

Why don’t scientists like using the word “Darwinism“?

Evolution is a normal field of science supported by facts and genetics, not a belief system named after one dead guy.